There are obvious enquiries to be made as to feasibility – and reproducibility - of BI techniques Therefore, it is good idea to bring up potential problems:
1. Beads will clog the flow channels.
2. The amount of injected beads is difficult to control.
3. The density of bead column packing will not be reproducible.
4. Stray beads will become trapped in channels, causing carryover.
5. The sample flow through the column will be channeled.
6. The beads cannot be completely removed from the flow cell.
7. Variation of light absorption by the beads will make spectroscopic measurement unreliable.
While the concept of BI was outlined more than 10 years ago, it took many attempts to design and perfect the method of capturing, packing and monitoring of beads to the point that BI-based assays became not only reproducible, but also suitable for routine use. Key components of the successful approach were the design of the “Lab-on-valve” module and precise programming of the flow rates and delivered volumes.
The following movie clip shows the feasibility of bead manipulation and metering in “Lab-on-valve” format. Note that the volume of beads delivered into the flow cell is exactly the same in the first injection (green beads) as in the second (blue beads).
Are BI Techniques Feasible?
3.1.7.
